If you want to work as a mobile app developer in 2021 but aren’t sure which programming language to start with, then I am sure you’ve come to the perfect spot.
App developers are in high demand as the need for mobile apps grows with each day. Both large and small businesses are recruiting app developers to develop their mobile apps, thus Android and iOS app developers are in high demand.
Although there are many programming languages available, not all of them seem to be appropriate for app development. That is why it is critical to understand the options and select the best programming language that will enable you to not only create apps for Android and iOS but also to become a more expert in app developer.
List of the Most Popular Programming Languages for App Development 
I have gone through a little wide introduction about this topic, now let’s dive into the main content you are looking for.
If you are ambitous about building an app for IOS or iPad, then you must learn Swift to do so. This language is very helpful in building apps for other then Android.
It has overtaken Objective C as the chosen programming language for iOS app development. Swift is my favorite programming language since it reminds me of Python. You should learn this language because it is also the official programming language for iOS, which is why you have to learn Swift for your iOS app development.
Swift may be used for server-side operations. Because most companies have their own framework or use one of the larger ones, this is still a novel notion that might be challenging to learn depending on where you work.
Swift includes a fantastic IDE called Xcode, which is self-contained. Swift is a type-safe language that is simple to read, comprehend, and code with, and it detects the majority of beginner mistakes at compile time.
Java is a popular, strong, and productive programming language that is in high demand for job and career advancement. While Java is generally a server-side programming language that is used to build sophisticated back end servers, it can also be used to develop Android applications.
Learning Java has several advantages for newcomers who desire to work as app developers. By establishing a back end in Java, you may not only design Android apps but also become a full stack developer.
If you’re serious about developing Android apps, Kotlin is the programming language to study in 2021. It’s most likely the next big thing in the Android universe.
Even though Java is my favorite programming language, Kotlin offers native support and is supported by several IDEs for Android development, including IntelliJ IDEA and Android Studio.
Koltlin is described as the next-generation Java, although it isn’t quite there yet. Compilation time is 2x to 3x that of Java. It allows the programmer to do functional programming with Lambdas.
The most compelling argument I can think of for learning Dart is Flutter, which makes creating cross-platform apps a simple. If you want to study Flutter, I recommend learning Dart programming.